can websites collect email addresses without user input?

[Vicki Falkland]

hi folks,

is it activex controls/code which can pick up a computer's email address
(resulting in spam mail) just by visiting a website? 
or is it something else  .... VBS ... ??

i'm getting some spam in an email account on a machine which was
(temporarily) used to demonstrate games and gamers websites. no information
or forms were submitted at any sites, but the spam still came in. 
its not a problem to deal with - just curious.

tia,
vf.